#include <iostream>

#include <list>

using namespace std;

​

int main() {

  list<string> cars = {"Volvo", "BMW", "Ford", "Mazda"};

​

  // Change the value of the first element

  cars.front() = "Opel";

​

  // Change the value of the last element

  cars.back() = "Toyota";

​

  cout << cars.front() << "\n";

  cout << cars.back() << "\n";

  return 0;

}

​